SCIENTIFIC COMMITTEE, JULY 18. 



CXVll 



Scientific Committee, July 18, 1911. 



Mr. E. A. Bowles, M.A., F.L.S., F.E.S., in the Chair, and fourteen 



members present. 



Botanical Certificates. — Catasetiim reflexuni, a new species, from 

 Peru, approaching Cycnoches in some of its characters, was sent from 

 Glasnevin by Sir Frederick Moore. On the motion of Mr. O'Brien, 

 V.M.H., seconded by Mr. Wilson, F.L.S., a Botanical Certificate was 

 'unanimously recommended tO' this plant. A new Dendrohium, from 

 Java, was exhibited by Sir Trevor Lawrence, Bart. It had been 

 described under the name of D. Annae, J. J. Smith, and is nearly allied 

 to D. mutahile (which was shown to compare with it), but about double 

 the size. On the motion of Mr. O'Brien, V.M.H., seconded by Mr. 

 Bennett-Poe, V.M.H., a Botanical Certificate was recommended. 



Scale on grass. — Mr. Holmes, F.L.S., showed a white scale insect 

 attacking grass from Charing. This scale (Uropeltis jestucae) appears 

 to be common this season in places, and proves destructive to the 

 grasses it attacks, causing them to become brown. 



Sweet Pea roots. — Mr. Holmes also showed dying roots of Sweet 

 Pea. These, as is so frequently the case this year, were attacked by 

 ■the fungus Thielavia hasicola. The foliage of attacked plants turns 

 yellow in patches, and finally dies, while the stem is often streaked with 

 yellowish-brown. The fungus also attacks the culinary Pea, and 

 produces similar symptoms. In America and Italy it has proved 

 extremely destructive to Tobacco, and nothing short of sterilization 

 of the soil has served to effectively check its ravages. 



Papaver orientate with cleistogamous flowers. — Mr. Fraser, F.L.S., 

 showed Palaver orientate with cleistogamous flowers. The plants had 

 produced similar flowers last year. The petals were linear-oblong, not 

 'imbricate, and only as long as the sepals. The pollen was abundant, 

 and both stamens and pistil appeared normal. 



Sport in Shirley Poppy. — Mr. Fraser also showed flowers of Shirley 

 Poppy having the usual yellow stamens, but with two of the petals red 

 and the two alternate ones white. 



Matricaria suaveolens. — Mr. Bowles showed specimens of Matricaria 

 suaveolens ( = M. discoidea), an introduced plant which now grows 

 wild in many English counties, and as far north as Aberdeen. The 

 specimens were collected in the neighbourhood of Epping. 



Crown-gall. — Mr. H. T. Giissow sent specimens of crown-gall — 

 ■ large swellings on the roots or near the collar of trees. These came 

 from Canada where the disease, as in the States, appears to be common 

 on a variety of plants. It has been shown by Dr. Erwin Smith to be 

 due to the attack of Bacillus tumefaciens, though others, apparently 

 without recourse to inoculation experiments, have ascribed it to the 

 attack of a Myxomycete. Numerous plants of widely distinct families 

 are attacked by the bacillus, but it does not yet seem to be clearly 

 established that is very harmful to the plant attacked. 



Fasciated Rose. — ^Mr. Basham, of Bassaleg, sent a fasciated Eose 



